pydoc
— 文档编制生成器和在线帮助系统
¶
源代码： Lib/pydoc.py
pydoc
module automatically generates documentation from Python modules. The documentation can be presented as pages of text on the console, served to a Web browser, or saved to HTML files.
For modules, classes, functions and methods, the displayed documentation is derived from the docstring (i.e. the
__doc__
attribute) of the object, and recursively of its documentable members. If there is no docstring,
pydoc
tries to obtain a description from the block of comment lines just above the definition of the class, function or method in the source file, or at the top of the module (see
inspect.getcomments()
).
The built-in function
help()
invokes the online help system in the interactive interpreter, which uses
pydoc
to generate its documentation as text on the console. The same text documentation can also be viewed from outside the Python interpreter by running
pydoc
as a script at the operating system’s command prompt. For example, running
pydoc sys
at a shell prompt will display documentation on the
sys
module, in a style similar to the manual pages shown by the Unix
man
command. The argument to
pydoc
can be the name of a function, module, or package, or a dotted reference to a class, method, or function within a module or module in a package. If the argument to
pydoc
looks like a path (that is, it contains the path separator for your operating system, such as a slash in Unix), and refers to an existing Python source file, then documentation is produced for that file.
注意
In order to find objects and their documentation,
pydoc
imports the module(s) to be documented. Therefore, any code on module level will be executed on that occasion. Use an
if
__name__
==
'__main__':
guard to only execute code when a file is invoked as a script and not just imported.
When printing output to the console,
pydoc
attempts to paginate the output for easier reading. If the
PAGER
environment variable is set,
pydoc
will use its value as a pagination program.
Specifying a
-w
flag before the argument will cause HTML documentation to be written out to a file in the current directory, instead of displaying text on the console.
Specifying a
-k
flag before the argument will search the synopsis lines of all available modules for the keyword given as the argument, again in a manner similar to the Unix
man
command. The synopsis line of a module is the first line of its documentation string.
还可以使用
pydoc
to start an HTTP server on the local machine that will serve documentation to visiting Web browsers.
pydoc -p 1234
will start a HTTP server on port 1234, allowing you to browse the documentation at
http://localhost:1234/
in your preferred Web browser. Specifying
0
as the port number will select an arbitrary unused port.
pydoc -b will start the server and additionally open a web browser to a module index page. Each served page has a navigation bar at the top where you can Get help on an individual item, 搜索 all modules with a keyword in their synopsis line, and go to the Module index , 话题 and Keywords 页面。
当
pydoc
generates documentation, it uses the current environment and path to locate modules. Thus, invoking
pydoc spam
documents precisely the version of the module you would get if you started the Python interpreter and typed
import
spam
.
Module docs for core modules are assumed to reside in
https://docs.python.org/X.Y/library/
where
X
and
Y
are the major and minor version numbers of the Python interpreter. This can be overridden by setting the
PYTHONDOCS
environment variable to a different URL or to a local directory containing the Library Reference Manual pages.
3.2 版改变：
添加
-b
选项。
3.3 版改变：
-g
command line option was removed.
3.4 版改变：
pydoc
now uses
inspect.signature()
而不是
inspect.getfullargspec()
to extract signature information from callables.